Dual fan coaxial flow blower housing assembly

ABSTRACT

A blower assembly including a housing for a first scroll fan and a second scroll fan that are connected by a shaft to a motor that rotates the fans. The first and second scroll fans are coaxially mounted on the shaft. Fresh air ports and recirculated air ports are provided for the circulation of fresh air and recirculated air, respectively. The fresh air ports and recirculated air ports may be selectively opened and closed by doors to control the flow of air from the outside and from the passenger compartment as controlled by the HVAC system.

TECHNICAL FIELD

This disclosure relates to vehicle heating ventilation and airconditioning (HVAC) system blower fans and blower housings.

BACKGROUND

Vehicle HVAC systems have a separate air inlet for fresh air and forrecirculated air. Air is directed from the fresh air inlet and/or therecirculated air inlet to the blower within the blower housing. Theblower housing structurally supports the blower fan. Blower housingswith separate fresh air inlets and recirculated air inlets may encounterproblems relating to noise levels and vibration.

Another problem encountered by vehicle HVAC systems is that they tend tobe bulky. As the volume of air moved through the system is increased,the space required to house the blower housing also increases. Spaceavailable for a blower housing in a vehicle is limited and may impactvehicle design freedom.

In HVAC systems having more than one fan, each fan typically has oneinlet that is shifted between a fresh air source and a recirculation airsource. Multiple fans are not used to draw fresh air and recirculatedair through the same inlet.

The above problems and other problems are addressed by this disclosureas summarized below.

SUMMARY

This disclosure is directed to a HVAC housing for a dual wheel/dualscroll fan blower that is assembled to a blower housing to create acoaxial air flow path within the blower housing. The blower housing mayhave integral internal ribs that direct air flow from the cowl air flowinlet and indirectly to the blower. The internal rib design in thecoaxial fan chamber also provides structural support for directlyassembling the fans, motor and other components to the blower housingassembly. The internal rib design reduces noise and vibrations whileimproving the flow of air into the blower inlet.

In one embodiment, the fresh air from the cowl air flow inlet may be theonly fresh air inlet that provides fresh air to both fans. Fresh air maybe provided to two more inlet openings from the cowl area to the fans.Recirculation air inlets may also be provided that may operate incombination with or independently of the fresh air inlets.

The dual wheel/dual scroll fan blower may be horizontally oriented,vertically oriented or oriented in any angular orientation required tomeet the packaging requirements in the limited space available for theHVAC blower housing assembly in a vehicle. The size of the HVAC blowerhousing assembly may be reduced due to increased efficiency of thecoaxial fans and, as a direct result, the size and weight of theinstrument panel may be reduced. A smaller HVAC blower housing assemblyallows more design freedom for instrument panel designs.

The HVAC blower housing assembly may facilitate providing a partialrecirculation strategy that permits part of the air flow to berecirculated with fresh air. Partial recirculation of air within thevehicle in combination with limited fresh air may reduce the load on theHVAC system and may permit system specifications to be less rigorous.

According to one aspect of this disclosure, a HVAC blower housingassembly is disclosed that includes a housing and a motor assembled tothe housing. A first fan and a second fan are operatively connected tothe motor and are coaxially aligned to draw air from a first inlet and asecond inlet, respectively. An outlet receives air from the first fanand the second fan and forces the air to the passenger compartment.

According to another aspect of this disclosure, a HVAC blower housingassembly is disclosed that includes a housing that defines a firstopening and a second opening. A motor is disposed within the housing andis connected to a first blower scroll fan and a second blower scrollfan. The first blower scroll fan is operatively connected to the motorthat draws air through the first opening. The second blower scroll fanis operatively connected to the motor that draws air through the secondopening. A first closure member controls the flow of air through thefirst opening by controlling the volume of air drawn from a fresh airsource and the volume of air drawn from a passenger compartment. Asecond closure member controls the flow of air through the secondopening from the passenger compartment.

According to further aspects of this disclosure, the HVAC blower housingassemblies summarized above may also include a jacket that defines anannulus disposed around the housing that facilitates air flow around thehousing from one end of the housing to the opposite end of the housing.A wide variety of fresh air and recirculated air inlets are disclosed.Different door combinations may be provided to control the sources ofair provided to the blower scroll fans. The blower scroll fans arecoaxially aligned and may be oriented vertically, horizontally or inanother orientation to suit packaging requirements and space limitationswithin an instrument panel.

The above aspects of this disclosure and other aspects will be morefully described in the following detailed description of the illustratedembodiments and with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a HVAC blower housing assemblyhaving recirculation air inlets on both ends of the assembly and a freshair inlet on one ends of the assembly that also provides fresh airthrough a partial annulus to the opposite end of the assembly.

FIG. 2 is a diagrammatic cross-sectional view taken along the line 2-2in FIG. 1.

FIG. 3 is a cross-sectional view of a HVAC blower housing assemblyhaving recirculation air inlets on both ends of the assembly and a freshair inlet on one end of the assembly that also provides fresh airthrough a cylindrical annulus to the opposite end of the assembly.

FIG. 4 is a cross-sectional view of a vertically oriented HVAC blowerhousing assembly having recirculation air inlets on both ends of theassembly and fresh air inlets on both ends of the assembly.

FIG. 5 is a cross-sectional view of a horizontally oriented HVAC blowerhousing assembly having recirculation air inlets on both ends of theassembly and fresh air inlets on both ends of the assembly.

DETAILED DESCRIPTION

The illustrated embodiments are disclosed with reference to thedrawings. However, it is to be understood that the disclosed embodimentsare intended to be merely examples that may be embodied in various andalternative forms. The figures are not necessarily to scale and somefeatures may be exaggerated or minimized to show details of particularcomponents. The specific structural and functional details disclosed arenot to be interpreted as limiting, but as a representative basis forteaching one skilled in the art how to practice the disclosed concepts.

Referring to FIG. 1, a blower assembly 10 is illustrated that includes ahousing 12. A motor 16 is disposed within the housing and is operativelyconnected to a first scroll fan 18 and a second scroll fan 20 by a shaft22. The first and second scroll fans 18 and 20 are coaxially aligned onthe shaft 22 and draw air from opposite ends of the housing because theyare oppositely oriented on the shaft 22. The first scroll fan 18 isconnected to a first end 26 of the shaft 22 and the second scroll fan 20is connected to a second end 28 of the shaft 22. The motor 16 rotatesthe shaft 22 to operate the first and second scroll fans 18 and 20.

A fresh air port 30 admits fresh air F into the housing 12. The freshair F is also selectively provided to the fresh air duct 32. The freshair duct 32 is a semi-annular duct that routes air around the first andsecond scroll fans 18 and 20. A fresh air door 34 may be shifted betweena position blocking the fresh air port 30 and an open position in whichfresh air F may be provided to the fresh air duct 32. A firstrecirculated air duct 36 provides recirculated air R. A firstrecirculated air door 38 may be opened and closed to permit or preventthe flow of recirculated air R through the first recirculated air duct36. The first recirculated air door 38 may be a pivoting door or a rollfilm door depending on cost and space requirements. A secondrecirculated air duct 40 is provided at the opposite or lower end of thehousing 12 and an alternate recirculated air duct 42 may also beprovided on the housing 12 to permit recirculated air R to flow intohousing 12. A combination door 44 may be moved to a blocking positionblocking the second recirculated air duct 40 and the alternaterecirculated air duct 42. The combination door 44 may also be moved toblock the flow of fresh air F through the fresh air duct 32.

Referring to FIG. 2, a diagrammatic representation of the apparatusshown in FIG. 1 is provided. The first scroll fan 18 is shown disposedwithin the housing 12. The fresh air duct 32 is shown to be asemi-annular duct attached to the outside of the housing 12. The firstscroll fan 18 is shown in operation expelling air into an outlet duct50. The air in the outlet duct 50 is outlet air that is provided to apassenger compartment 52.

Referring to FIG. 3, a blower assembly 54 is shown that includes ahousing 56. The blower assembly 54 is attached to a bulkhead 58 by afastener 60. A cowl 62 is also shown at one end of the housing 56 thatseparates the interior of the vehicle (not shown) from the exterior.

A motor 64 is assembled to the housing 56 and bulkhead 58 by motor mountribs 66 that operatively support the motor 64 within the housing 56. Afirst scroll fan 68 and a second scroll fan 70 are provided on oppositeends of a shaft 72. The shaft 72 is rotated by the motor 64 to provideair flow by rotation of the scroll fans 68 and 70.

A fresh air port 76 is defined by the cowl 62 and the housing 56. Freshair F is supplied to the blower housing assembly 54 through the freshair port 76 when a fresh air door 78 is opened. Fresh air door 78 may beclosed to operate the blower housing assembly 54 in a recirculationmode. A fresh air duct 80 is provided that encloses the housing 56. Thefresh air duct 80 may be a cylindrical annulus through which fresh airis permitted to flow from the fresh air port 76 through a plurality ofacoustic air flow ribs 82 to the opposite ends of the blower assembly54. The acoustic air flow ribs 82 support the housing 56 within thefresh air duct 80 and are constructed to eliminate unwanted noise in theblower assembly 54. A first recirculated air duct 84 is provided in thefresh air duct 80 adjacent the fresh air port 76. Recirculated air R isadmitted through the first recirculated air duct 84 from the passengercompartment 52 (shown in FIG. 2). The first recirculated air duct 84 maybe opened and closed by a first roll film door 86 depending upon whetherair is requested to be recirculated through the blower assembly 54. Asecond recirculated air duct 88 is provided on the opposite end of theblower assembly 54 from the fresh air port 76. A second roll film door90 may be provided that opens and closes the second recirculated airduct 88 to either permit or restrict air from being recirculated by theblower housing assembly 54.

Referring to FIG. 4, another alternative embodiment of a blower assembly96 is illustrated. A housing 98 of the blower assembly 96 is attached toa cowl 100 of the vehicle (not shown).

A first scroll fan 106 and a second scroll fan 108 are attached toopposite ends of a shaft 110. A motor 102 operates the scroll fans 106and 108, as previously described. A first fresh air port 112 is providedthrough the cowl 100 and may be opened and closed by a first fresh airdoor 114. A second fresh air port 116 is provided near the other end ofthe housing 98 and is adapted to be opened and closed by a second freshair door 118. The second fresh air port 116 may receive air from theouter side of the bulkhead (not shown) that is similar to the bulkhead58 shown in FIG. 3. A second fresh air door 118 may be opened and closedto allow fresh air F to flow into the housing 98. A first recirculatedair duct 120 is provided in the housing 98 near the first fresh air port112. A first roll film door 122 is provided to open and close the firstrecirculated air duct 120. A second recirculated air duct 124 isprovided in the opposite end of the housing 98 from the first fresh airport 112. The second recirculated air duct 124 may be opened and closedby a second roll film door 126, as previously described.

Referring to FIG. 5, a horizontal blower assembly 130 is illustratedthat includes a housing 132 that is adapted to be secured below the cowl134 of the vehicle (not shown). A motor 136 is operatively connected toa first scroll fan 140 and a second scroll fan 142 by a shaft 144.

A first fresh air port 146 is provided in the housing 132 on the leftside of FIG. 5. The first fresh air port 146 may be opened and closed byrotating a dual function door 148 to open and close the first fresh airport 146. A second fresh air port 150 may be provided between the cowl134 and housing 132. The second fresh air port 150 is adapted to beopened and closed by a second fresh air door 152. A first recirculatedair duct 154 may be provided in the housing 132 to permit air to berecirculated in the passenger compartment 52 (as shown in FIG. 2). Thedual door 148 may be used to open and close the first recirculated airduct 154 by rotating the dual door 148 between the position shown inFIG. 5 in solid lines and a position shown in phantom lines in FIG. 5.

A second recirculated air duct 158 is provided in the opposite end ofthe housing 132 from the first recirculated air duct 154. The secondrecirculated air duct 158 may be opened and closed by a roll film door160, as previously described.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the disclosed apparatusand method. Rather, the words used in the specification are words ofdescription rather than limitation, and it is understood that variouschanges may be made without departing from the spirit and scope of thedisclosure as claimed. The features of various implementing embodimentsmay be combined to form further embodiments of the disclosed concepts.

What is claimed is:
 1. A HVAC blower assembly comprising: a housing; amotor assembled to the housing; a first fan and a second fan operativelyconnected to the motor, the first fan and the second fan being coaxiallyaligned to draw air from a first inlet and a second inlet, respectively;and an outlet that receives the air from the first fan and the secondfan and passes the air to a passenger compartment.
 2. The assembly ofclaim 1 further comprising: a shaft that is driven by the motor andextends from first and second opposite ends of the motor, and whereinthe first fan is connected to a first end of the shaft and the secondfan is connected to a second end of the shaft.
 3. The assembly of claim2 wherein the housing further comprises a first air inlet that the firstfan draws air into the housing, and a second air inlet that the secondfan draws air into the housing.
 4. The assembly of claim 3 wherein thefirst fan draws air including recirculated air from the passengercompartment and fresh air from outside of the passenger compartment. 5.The assembly of claim 1 wherein the first fan draws air includingrecirculated air from the passenger compartment and fresh air fromoutside of the passenger compartment.
 6. The assembly of claim 1 whereinthe second fan draws air including recirculated air from the passengercompartment and fresh air from outside of the passenger compartment. 7.The assembly of claim 1 wherein the first fan and the second fan arecoaxially aligned in a vertical orientation.
 8. The assembly of claim 1wherein the first fan and the second fan are coaxially aligned in ahorizontal orientation.
 9. The assembly of claim 1 wherein the first fanand the second fan are coaxially aligned in an angular orientation thatis between vertical and horizontal.
 10. A HVAC blower assemblycomprising: a housing that defines a first opening and a second opening;a motor disposed within the housing; a first blower scroll fanoperatively connected to the motor that draws air through the firstopening; a second blower scroll fan operatively connected to the motorthat draws air through the second opening; a first closure member thatcontrols air flowing through the first opening by controlling a firstvolume of air from a fresh air source and a second volume of air from apassenger compartment; and a second closure member that controls airflowing through the second opening from the passenger compartment. 11.The assembly of claim 10 wherein the second closure member controls airflowing through the second opening from the fresh air source.
 12. Theassembly of claim 11 further comprising: an outside air vent thatprovides air from the fresh air source to both the first opening andsecond opening.
 13. The assembly of claim 12 further comprising a freshair duct provided on the housing that extending from the first openingto the second opening to provide fresh air to the second opening. 14.The assembly of claim 11 further comprising: a first outside air ventthat provides air from the fresh air source to the first opening; and asecond outside air vent that provides air from the fresh air source tothe second opening.
 15. The assembly of claim 10 further comprising: aplurality of ribs formed inside the housing for supporting the motor andthe first blower scroll fan and the second blower scroll fan within thehousing.
 16. The assembly of claim 10 further comprising: a plurality ofacoustic air flow ribs formed inside the housing in an air outlet fromthe housing that also include a motor mount.
 17. The assembly of claim10 further comprising: a shaft that is driven by the motor and extendsfrom first and second opposite ends of the motor, and wherein the firstblower scroll fan is connected to a first end of the shaft and thesecond blower scroll fan is connected to a second end of the shaft. 18.The assembly of claim 10 further comprising: an outlet that receives theair from the first blower scroll fan and the second blower scroll fanand passes the air to a passenger compartment.